A summary of Commonwealth environmental watering from previous years in the Warrego is included below. For further information about the Commonwealth environmental watering in the Warrego and the outcomes achieved, please refer to the Commonwealth environmental water Outcomes Reports and Annual Reports.

Environmental watering in the catchment in previous years

There was no Commonwealth environmental watering undertaken in the Warrego catchment in 2012-13.

Environmental watering in the catchment in 2011-12

Watering action

Amount of water delivered (ML)

Status of action

Upper Warrego

6 050

Completed

Lower Warrego

10 000

Completed

Lower Warrego (Toorale)

8 016

Completed

Lower Warrego Wester Floodplain (Toorale)

9 720

Completed

Total in 2011-12

33 786

Environmental watering in the catchment in 2010-11

Watering action

Amount of water delivered (ML)

Status of action

Upper Warrego

6 050

Completed

Lower Warrego

10 000

Completed

Total in 2010-11

16 050

Catchment profile

Where is it?

The confluence of the Warrego River and the Darling River. Photo by Adam Flanagan, CEWO

The Warrego Catchment is predominantly in Queensland and spans the area from the Carnarvon Range at the northernmost point of the Murray-Darling Basin to the Darling River in northern New South Wales. It is bounded to the east by the Condamine-Balonne region, to the west by the Paroo region and forms the northern edge of the MDB. The region is generally flat with a gentle southwards gradient. The upper catchment of the Warrego River includes the Warrego and Chesterton ranges.

It covers a total area of 87,749km2, or 8.4 per cent of the Murray-Darling Basin. Tributaries to the Warrego include the Nive and Langlo Rivers. The Warrego River enters the Darling River downstream of Bourke, and during times of flood is connected to the Paroo River via Cuttaburra Creek. This system is one of the last unregulated systems in the MDB.

Legend

Ramsar site

DIWA site

What makes this place so special?

The Warrego catchment is an ecologically significant area because it includes:

a diverse range of other fish communities including bony herring, golden perch and Australian smelt

species listed under the NSW Threatened Species ACT 1995 (TSC Act) including Major Mitchell's cockatoo and brolga

wetlands covering a total area of approximately 345,000 ha which are of critical importance to waterbird populations of the MDB.

Many wetlands in the Warrego River catchment are recognised as being of national importance; the two which have been most extensively researched are Yantabulla Swamp and the Warrego River Waterholes.

Yantabulla Swamp is part of the Cuttaburra Basin system, which is filled from various sources including Cuttaburra Creek and Paroo River overflow. The swamp covers over 37,000 ha and has been identified as the most important waterbird breeding site in north-west NSW. The main vegetation communities are cane grass, lignum, fringing yapunyah, river red gum, coolabah and river cooba.

The Warrego River Waterholes are a string of large permanent and intermittent waterholes covering some 500 ha along the river channel in Queensland. These sites are flooded seasonally in most years. They provide an invaluable habitat and refuge for a wide range of aquatic fauna including species listed under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) such as Murray cod. Significant waterbird populations are known to inhabit the waterholes particularly during periods of high flows.

What does the latest science say about the ecological health of the catchment?

The Sustainable Rivers Audit (SRA), coordinated by the Murray-Darling Basin Authority, provides scientifically robust assessments of the ecological health of the Basin's river valleys. The overall ecosystem health of the Warrego catchment as reported by the SRA is summarised below.

The CSIRO Sustainable Yields Report on the Warrego indicated that the current level of surface water extraction is very low. Surface water use is strongly influenced by the seasonal rainfall patterns which dictate runoff and stream flow; use varied between about 2 GL to 11 GL per year between 1993 and 2005. This represents less than one per cent of the surface water use in the MDB. The best estimate 2030 climate scenario indicates a six per cent reduction in river inflows leading to a seven per cent reduction in total end-of-system flows.

Note that the boundaries of this catchment as defined by the Sustainable Rivers Audit and the Sustainable Yields report differ slightly to the boundaries used here.